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Errors are a normal part of building. The good news: Fabricate checks your app for errors as it builds and can fix them. This page explains how that works and catalogs the errors you’re most likely to see.

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How Fabricate fixes errors

After each deploy, Fabricate opens your app’s live preview in its own browser, reads any errors, and fixes what it finds before it finishes. If an error still gets through:
1

An error appears in the preview

The running app shows an error or a blank screen instead of rendering.
2

Describe what you see

Send a follow-up message that says what you did and what happened.
3

Fabricate reads the error

It checks the preview in its own browser and reads the relevant code — the context needed to diagnose it.
4

The fix is applied

Fabricate deploys a fix and the preview refreshes. If the first fix doesn’t fully resolve it, describe what you still see.
Fabricate’s checks catch runtime errors — errors in the app while it runs. For a result that’s wrong but not technically erroring, just describe what’s off in a follow-up message.

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Build errors

Errors that surface while Fabricate is generating code.
When a deploy fails, Fabricate sees the error and usually fixes it on its own. If a build stops at its credit ceiling, select Continue build; if it was interrupted, select Resume build. Otherwise, send a short follow-up — “the last change didn’t finish, please complete it” — so it can pick up where it left off.
Generated apps use TypeScript, but types aren’t checked when your app is bundled, so a type mistake shows up as a runtime error or wrong behavior rather than a build error. Describe what you see: “The tasks page shows an error when I open a task — fix it.”
The build completed, but part of your request wasn’t covered. Reply naming the gap: “The build finished, but the delete button isn’t on the task cards yet — please add it.”

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Runtime errors

Errors that appear in the live preview while the app runs. These are what Fabricate’s browser checks look for.
A blank preview usually means a JavaScript error stopped the app from rendering. Describe it: “The home page renders blank — find the error and fix it.” A blank app is also blocked from publishing until it renders.
The app tried to use data that wasn’t loaded yet or doesn’t exist. Fabricate fixes this by handling the loading and empty states. Say “Add proper loading and empty-state handling to the page that’s erroring.”
A page request to the backend is failing — often a route, query, or auth issue. Describe it: “The projects list shows an error instead of loading — check the API route and fix it.” Fabricate can trace the request from frontend to API to database.
A handler may be missing or wired up wrong. Be specific: “The Save button on the task form doesn’t do anything when clicked — make it save the task and close the dialog.”
Generated apps with accounts use Fabricate’s built-in email-and-password sign-in. If a flow misbehaves, describe the exact behavior: “After I sign up I’m not logged in automatically — fix it so signup logs the user straight in.”
If the app renders but looks plain or misaligned, a styling issue slipped in. Screenshot it from the preview and attach it — see Working with Images — then ask Fabricate to fix the affected page.

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Getting the best fix

1

Point Fabricate at runtime errors

Say which page or action triggers the error — Fabricate can open the preview in its own browser and read it.
2

Describe behavior precisely for everything else

Say what you did, what you expected, and what happened instead.
3

Attach a screenshot when it's visual

A picture from the preview removes any guesswork.
4

Revert if a fix makes things worse

Go back to an earlier version with version history and try a clearer prompt.
If the same error keeps coming back, the underlying request may be ambiguous. Ask Fabricate to explain the right approach first — say you don’t want changes yet — then build it. See Prompting Best Practices.

Troubleshooting

Solutions for non-error issues like stuck builds.

Building in the Chat

Understand how changes and fixes are generated.